How to convert a file extention?

Like .jar to .sis?

People say change the name and extension.

Is it possible by changing the file name via 'Rename'?

Or is it some other method?How to convert a file extention?very possible to change via Rename.....but it will not work....!How to convert a file extention?If you are sure just changing the extension of the file you need to change is going to keep the file functional, you can simply use %26quot;Rename%26quot;. If you are having trouble seeing the extensions, open an explorer window (like my documents or my computer), click on the tools menu, select folder options from the drop down menu. Select the view tab, look for %26quot;Hide Extensions for known file types%26quot; and uncheck the box. This will show all extensions instead of hiding them.How to convert a file extention?can't convert by just changing the file name